Conventionally, there is known a system to perform various controls such as locking and unlocking a door or starting an engine of a vehicle based on that wireless communication successfully verifies an in-vehicle apparatus mounted to the vehicle and a vehicular portable device that is carried by a user and is associated with the in-vehicle apparatus.
Patent Literature 1 discloses a system (hereinafter referred to as a user identification system) that uses the above-mentioned system to identify a user going to get into a vehicle and thereby automatically changes settings including an interior environment such as a seat position to a predetermined user-specific interior environment.
The user identification system disclosed in Patent Literature 1 allows a user's mobile terminal (such as a mobile phone) to previously register user information used as an indicator to specify a user. Suppose the user enters a wireless communication area for the in-vehicle apparatus while carrying both the vehicular portable device and the mobile terminal. In this case, the vehicular portable device uses intra-body communication to acquire the user information from the mobile terminal and transmits the acquired user information to the in-vehicle apparatus. The in-vehicle apparatus specifies the user based on the user information received from the vehicular portable device and changes the interior environment setting to the one suited for the user preference.
As a modification, Patent Literature 1 discloses that a manner of communication between the vehicular portable device and the mobile terminal may be near field communication whose communicable distance approximates several centimeters. Anyway, the supposed manner uses only one mobile phone existing at a position capable of communication with the vehicular portable device.